This study is an investigation of the endogenous, or internal,
rhythms of activity in the ocean shrimp, Pandalus jordani, Groups
of shrimp were kept in constant light and temperature conditions in
the laboratory, and activity was monitored visually and with infrared
photography. Other groups of animals were exposed to 24-hour light-.
dark cycles of blue-green light; the activity of these animals was
recorded with infrared photography after the light cycle was terminated.
It was found that shrimp not exposed to a light-dark cycle did not
display any rhythms of activity in constant conditions in the laboratory.
After exposure to the light cycle, some shrimp swam significantly
more during the 'night" hours in constant conditions. These
shrimp 'entrained" to the light cycle; they synchronized their activity
with the periodicity of the light cycle, and retained the periodicity in
the absence of the rhythmical light cues.
The relationship of these results to the nocturnal vertical migration
of ocean shrimp in the field is discussed. It is suggested that
shrimp possess a biological clock which synchronizes with rhythmical
light cues and mediates vertical swimming, and that the rhythmicity
of the vertical migration in the field is endogenous, with internal and
external factors interracting with the internal rhythm. Conclusions
are summarized and areas for further research are suggested. / Graduation date: 1974
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28425 |
| Date | 11 May 1973 |
| Creators | Frey, John Richard |
| Contributors | Pearcy, William G. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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